In the 3rd Generation Partnership Project (3GPP), a radio access method and a radio network for cellular mobile communications (hereinafter referred to as “Long Term Evolution (LTE)”, or “Evolved Universal Terrestrial Radio Access (EUTRA)”) have been considered (NPL 1, NPL 2, NPL 3, NPL 4, and NPL 5). In LTE, a base station device is also referred to as an evolved NodeB (eNodeB), and a terminal device is also referred to as user equipment (UE). LTE is a cellular communication system in which an area is divided into a plurality of cells to form a cellular pattern, each of the cells being served by a base station device. In such a cellular communication system, a single base station device may manage multiple cells.
LTE supports a time division duplex (TDD). LTE that employs a TDD scheme is also referred to as TD-LTE or LTE TDD. In TDD, uplink signals and downlink signals are time division multiplexed. Furthermore, LTE supports a frequency division duplex (FDD).
In 3GPP, carrier aggregation has been specified which allows a terminal device to perform simultaneous transmission and/or reception in up to five serving cells (component carriers).
In addition, in 3GPP, a configuration where a terminal device performs simultaneous transmission and/or reception in more than five serving cells (component carriers) has been considered (NPL 1). Furthermore, a configuration where a terminal device transmits a physical uplink control channel in a secondary cell which is a serving cell other than a primary cell has been considered (NPL 6).